Configuring SNMP OID for Memory Utilization Monitoring

1. In this article we look at how to configure the SNMP OID for memory utilization monitoring of specific device. If you do not know the OID for a device, contact the device manufacturer and request the OID for the function required.

Procedure

Step 1. Right-click on the device that required RAM utilization monitoring and select View Device Info.

Step 2. The View Device Info window opens. Click on SNMP OID.

Step 3. The SNMP OID window opens. Examine the entries for “platform specific oid memory utilization.” In this case two OID entries have been made. Depending on the manufacturer, one or two entries will be entered.

Step 4. If there are no entries, then SNMP OID need to be entered to enable the memory utilization monitoring.

Step 5. To enter platform specific OID for memory utilization, click on the text.

Step 6. The SNMP OID (memory utilization) window appears.

The manufacturer will tell you how the device reports memory utilization. If the device reports Memory Utilization Percent directly, the OID is entered in that box and provisioning is done. If the device reports separate values for total, free or used, then the OID information for each count need to be entered. Nectus will perform the calculation to arrive at Memory Utilization.

For example, when the device reports Memory Utilization Percent directly, the OID is entered in the first box and provisioning is complete.

In this case, the device reports Memory Used and Memory Free, so the OID for Memory Used is entered in the Memory Used space and the OID for Memory Free is entered in the Memory Free space. Nectus will compute utilization as Memory Used / (Memory Used + Memory Free) * 100.

In this case, the device reports Memory Free and Memory Total, so the OID for Memory Free is entered in the Memory Free space, and the OID for Memory Total is entered in the Memory Total space. Nectus will compute utilization as Memory Free / Memory Total * 100.

Step 7. Click on the OK button. Nectus will provision the OID information, unless an error is discovered.

In this case Nectus is reporting that Used and Free Memory OIDs are required.

We re-enter the OID information as Memory Used and Memory Free, and click OK.

Step 8. The OID assignments are accepted and displayed on the View Device window.

Testing

1. Testing: Testing the assignments can be done by examining the utilization display or retrieving the OID contents.

Step 1. Click View Device → General to see the results of configuration.

RAM percent utilization is working.

Step 2. Testing: Click on the dial to see a graph of the measurement over time.

Step 3. Testing: To retrieve current value of OID select SNMP OID tab and click on “TEST” for OID of interest.

Step 4. Change SNMP Walk to GET.

Step 5. Click Start.

Step 6. Current value of the OID will be displayed.

UPS Status Monitoring with Nectus

Health monitoring of UPS units is one of the most critical tasks of network infrastructure monitoring.

If UPS fails during power outage it results in immediate network downtime resulting in loss of revenue and degrading user experience.

Most of the modern UPS Units perform daily self-tests and results of those self-tests are available via SNMP protocol.

Our goal is to collect those self-test results on regular basis and generate an alert or incident when self-test indicates a UPS failure.

Step 1. Determine which SNMP OID to use

Very first step before you can start monitoring UPS health status is to determine which SNMP OID contains self-test information for your UPS units.

You can open a support case with your UPS vendor and request SNNP OID string for self-test information.

For example, SNMP OID for self-test information from UPS manufactured by APC is .1.3.6.1.4.1.318.1.1.1.7.2.3.0

This OID returns following values:

1 = Ok

2 = Failed

3 = Invalid Test

4 = Test In Progress

Step 2. Create Device View that contain all UPS units

Next step is to create a Device View that contain all UPS units that we want to monitor.

To create a Device View go to Inventory -> Views -> SNMP Device Views.

Create a new Device Vice called “UPS Units”

Step 3. Create Custom SNMP Tracker for UPS Self-Test Info

Now we are ready to create a custom SNMP tracker that will be polling our UPS units every 5 min for self-test information.

In Nectus GUI go to Monitoring → SNMP Monitoring Settings → Custom SNMP Trackers

Press “Create” button to bring up Custom SNMP Tracker creation interface.

Complete tracker General information tab with correct SNMP OID and select Device View that contains all UPS units that we want to monitor.

Select Email and SMS list for Alert Recipients.

In “Alerts” Tab we need to specify which status values will be considered Normal and which values should trigger Alerts.

You can specify multiple values separated by comma.

Define an Alert Severity level for Alarm Values as Informational, Warning or Critical.

Define number of consecutive readings for which UPS self-test status must report an Alarm condition before formal Alert is created.

Nectus performs one SNMP poll per 5 min.

If you define value for consecutive readings as 3 it should result in Alert created after 15 minutes of True Alarm conditions.

Press “Save” to complete Custom SNMP tracker creation for UPS Status Monitoring

This completes creation of custom tracker that will be monitoring UPS self-test information on all APC UPS units in your network.

Adjusting Min. detectable ICMP outage duration in Nectus

When Nectus is configured to monitor UP/DOWN Status for network devices with ICMP it sends Echo packets at preset interval called Inter-Packet Delay.

By default, this Interval is set to 10 seconds.

Network Device is considered down if Echo-Reply is not received for “N” consecutive Echo packets.

By default “N” is set to 10.

So, by combining Inter-Packet Delay and “N” Value we can see that minimum duration of the outage that can be detected by Nectus with default settings is 100 seconds.

Sometimes when network a prone to fast transient outages or burstable traffic patterns that can impact ICMP it may be beneficial to increase minimum detectable ICMP outage duration to higher value. This can helps to eliminate alerts about short lived outages and only alert on outages that have more lasting impact.

To adjust Inter-Packet Delay or “N” Value go to “Monitoring -> Global Monitoring Settings”

And adjust values on “ICMP Monitoring” Tab according to your business needs.

Multiple Alert Email Aggregation in Nectus

Very often during site level power or network outages or during network maintenance multiple devices become offline at the same time causing multiple individual DOWN Email alerts to be sent at the same time.

Depending in the size of the site it can be well over hundreds or even thousands alert emails to be sent out to corresponding e-mail recipients configured for given site.

Starting from version 1.2.52 Nectus offers an option to aggregate multiple DOWN or UP email alerts into a single multi-device alert notification containing a list of all devices that became DOWN or UP within last monitoring interval.

To enable Alert Aggregation, go to Monitoring -> Global Monitoring Settings: “Alert” Tab

And Select “Aggregate multiple UP/DOWN Alerts” Option.